The first known documentation of Dachau occurs in a medieval deed issued by the Noble Erchana of Dahauua to the prince-bishop of Freising, both descendants of the lineage of the Aribonids. With this deed, dated to August 15, 805 A.D. (the Feast of the Assumption of the Blessed Virgin Mary), she donated her entire property in Dachau, including five so-called Colonenhöfe and some serfs and bondsman, to devolve to the Bishop of the Diocese of Freising after her death.
The first prisoners arrived in Dachau on March 22, 1933, two days after the acting Munich Chief of Police and Reichsführer SS Heinrich Himmler announced the camp’s creation. Many of the initial prisoners were Social Democrats and German Communists, the latter group having been blamed for the February 27 fire at the German parliament building, the Reichstag.
Dachau is 20 km (12 mi) northwest of Munich. It is 482 meters above sea level by the river Amper, with a boundary demarcated by lateral moraines formed during the last ice age and the Amper glacial valley. It is also close to a large marshy area called Dachauer Moos. Highest elevation of the district is the so-called "Schlossberg", the lowest point is near the neighborhood of Prittlbach, at the border to the next community of Hebertshausen. The bordering communities are Bergkirchen to the west, Schwabhausen to the northwest, Röhrmoos to the north, Hebertshausen to the northeast, and Karlsfeld to the south. To the east the greater district Dachau borders on the greater district of Munich with the community of Oberschleißheim.
The fire signaled the demise of German democracy. On the next day, the government, under the pretense of controlling the Communists, abolished individual rights and protections: freedom of the press, assembly, and expression were nullified, as well as the right to privacy. When the elections were held on March 5, the Nazis received nearly 44 percent of the vote, and with 8 percent offered by the Conservatives, won a majority in the government.
The camp was liberated on April 15, 1945, by the British 11th Armoured Division. The soldiers discovered approximately 60,000 prisoners inside, most of them half-starved and seriously ill, and another 13,000 corpses, including those of Anne and Margot Frank, lying around the camp unburied. The horrors of the camp, documented on film and in pictures, made the name "Belsen" emblematic of Nazi crimes in general for public opinion in many countries in the immediate post-1945 period. Today, there is a memorial with an exhibition hall at the site.